Their database only contains cached results from previous searches. Kayak doesn't store the entire population of flights themselves - they forward users' queries onto a 3rd party flight inventory provider (ITA Software), then cache the results to power services like these.
This means that results are likely to be current and complete on popular routes, but far less so on the long tail.
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Their database only contains cached results from previous searches. Kayak doesn't store the entire population of flights themselves - they forward users' queries onto a 3rd party flight inventory provider (ITA Software), then cache the results to power services like these.
This means that results are likely to be current and complete on popular routes, but far less so on the long tail.
If I had to guess, they probably cache as aggressively as their contract with ITA allows because Kayak gets charged per search by ITA.
*edit: From the two ITA contract that I know/have heard about anyways.
And from what I know, ITA doesn't allow you to cache at all.